code: def reader(self):
      return self.in_memory_fx_rate_reader
  
imports: import itertools
  import pandas
  import numpy
  from zipline.data.fx import DEFAULT_FX_RATE
  from zipline.testing.predicates import assert_equal
  import zipline.testing.fixtures
label_desc: Use image node_id 1 for calling the InMemoryFXReaderTestCase obj's underlying member method code with example usage: obj.reader() and returns: self